Method and system of automatic bandwidth detection

ABSTRACT

A method for measuring a bandwidth of a signal path between a data source and a data recipient involves sending a block of test data from the data source along the signal path to the data recipient, using that test data to obtain a measured bandwidth of the signal path, and transferring information from the data source along the signal path to the data recipient in accordance with the measured bandwidth. The measured bandwidth value can be calculated each time the data recipient accesses a website or the measured bandwidth value can be retained for future use.

FIELD OF THE INVENTION

[0001] The present invention is directed to the transmission of databetween computers, and, more particularly, to a method of controllingthe supply of streaming media sent from a server to a client over theInternet.

BACKGROUND OF THE INVENTION

[0002] With the continuing expansion of the Internet the transfer ofdata between different computers over the Internet is becoming ever morewidespread. Computers today exchange data over the Internet using avariety of different types of connections. Connections such as T-1 andT-3 lines, cable modems, and DSL have high data transfer rates,typically on the order of 100-1000 Kbits/sec., and are referred to ashigh bandwidth or broadband connections. Connections such as telephonymodems have lower data transfer rates, typically on the order of 15-56Kbits/sec., and are characterized as low bandwidth connections.Bandwidth is important because it affects to the amount of data whichcan be passed between computers over the Internet. The term “data” isused broadly and, by way of example, refers to any type of informationthat can be transmitted over the Internet, such as numbers, text,images, sounds and computer programs.

[0003]FIG. 1 is a schematic view showing a number of client computersC₀, C₁, C₂ and C₃ and server computers S₀, S₁ and S₂ all connected tothe Internet. Client C₁ and server S₁, it should be noted, are joined tothe Internet by wireless connections.

[0004] Data sent over the Internet may vary in size greatly, dependingupon the nature of the data which is sent. One particularly bulky typeof data is streaming media data. The term “streaming media” refers toaudio, video or audio-video data with or without text that has achronological component and which is therefore played over time.Streaming media data is typically transferred from a content provider toa user. When this transfer takes place over a network, the contentprovider uses a server computer having the appropriate server softwareto respond to requests for data, and the user employs a computer havingthe appropriate client software to send requests for data and receiveand process responses to those requests.

[0005] Users typically exchange data over the Internet using Internetbrowser software. Browsers are capable of displaying a wide variety ofdifferent file formats that are commonly sent over the Internet, such asTIFF, JPG, HTML, TXT, WAV and so forth. Examples of browsers includeNetscape Navigator® by Netscape Corporation and Internet Explorer® byMicrosoft Corporation. Since the operation of browser software isgenerally known, such operation will not be described in detail.

[0006] In some instances, a browser may be unable to display the datasent by a content provider's server because that data is in anunsupported file format. In that case the browser may require asupplemental “plug-in” program to display the data. Such plug-inprograms can be written as Java applets or ActiveX controls. A widerange of different types of plug-in programs are known.

[0007] One type of data that generally cannot be displayed by a browseris streaming media data. When receiving streaming media data a browserwill call up a particular type of plug-in program known as a mediaplayer to process and display such data. The media player cooperateswith the browser and displays the streaming media data as that dataaccumulates in a buffer in the user's client computer. Typically, thebrowser program calls up the media player plug-in, which in turn callsthe objects that drive the media player, as downloading of the streamingmedia data from the content provider's server computer to the user'sclient computer begins.

[0008] Examples of media player programs include Quicktime® by AppleComputer, Inc.®, RealPlayer® by RealNetworks®, and Windows Media Playerby Microsoft Corporation.

[0009] Streaming media can be sent over the Internet using UDP (UserDatagram Protocol). According to UDP, packets of compressed audiovisualdata are sent from the content provider to the user over the Internetwithout verification that all packets have been received. By avoidingsuch verification data transfer is speeded. The data packets are storedat the user's computer in a buffer until the buffer fills, at whichpoint the media player program begins playing the media. Data packetscontinue to be delivered to the buffer as the media plays, hence thename “streaming”. In this way, the media player begins playback beforeall of the streaming media data is received, and can continue playbackuntil the buffer runs out of data.

[0010] Preferably, the content provider's server sends the userstreaming media data in a form which is optimal for the bandwidth of theuser's Internet connection. If the bandwidth of the user's connection ishigh, the server can send detailed streaming media data, resulting in alarge, lifelike and smooth display. If the bandwidth is low, less datashould be sent, resulting in a smaller and lower-quality image.

[0011] Included with the streaming media data sent by the contentprovider's server to the user may be information instructing the user'scomputer how to configure the media player to display the streamingmedia data. That is, high resolution streaming media data may beaccompanied by an instruction to the user's computer to display thestreaming media in a large media player window. Low resolution streamingmedia data may be accompanied by an instruction to the user's computerto display the streaming media in a small media player window.

[0012] For good playback quality the streaming media data should besupplied to the media player at least as quickly as the media player candisplay that data. If the media player display the streaming media datafaster than such data is received, the data buffer will empty, afterwhich jerking, skipping and poor quality playback will occur. This is aparticular problem for users having low bandwidth Internet connections;the low bandwidth connections mean users either will receive low-qualitydisplays, or, since their computers may not receive fresh streamingmedia data fast enough for proper display, may experience jerking andskipping of the program being played. It is therefore very importantthat the content provider send to the user streaming media data of theappropriate type and at the correct rate. This can be done in a numberof ways, for example, by reducing the size of the displayed image,decreasing the image's frame rate (frame rate refers to the number oftimes per second that the displayed image changes), and decreasing thequality of the accompanying audio playback.

[0013] Thus, when sending streaming media data from a content provider'sserver to a user's client, it is preferable that the server know thebandwidth of the user's Internet connection. This way the contentprovider can send data to the user at the appropriate rate, and in theappropriate format (i.e., resolutions and size).

[0014] Although this problem can to some extent be solved by having thecontent provider's server send streaming media data with the assumptionall users have low bandwidth connections, this would disadvantageouslyreduce the quality of the playback for those users having high bandwidthconnections.

[0015] Another solution to this problem is to control the quality ofstreaming media playback according to the known bandwidth of the user'sInternet connection; users having high bandwidth Internet connectionswould receive higher resolution data than users having low bandwidthInternet connections. To do this, websites distributing streaming mediacontent may wait to send streaming media data until the user hasindicated the bandwidth of their Internet connection. This way,streaming media data appropriate for the bandwidth of the user'sInternet connection can be sent. One way to accomplish this is to placeon the appropriate web page at the content provider's website differenthyperlinks corresponding to different possible Internet connectionbandwidths. Each hyperlink, when activated (“clicked”) sends informationto the content provider about the user's bandwidth, and may beaccompanied by a request to transfer to the user's computer specificresolution streaming media data. For example, users might be offered achoice of two different high bandwidth connections speeds, i.e., 300Kbps and 100 Kbps, and two different low bandwidth connection speeds,i.e., 56 Kbps and 28.8 Kbps. Each hyperlink would, when activated,inform the content provider of the user's bandwidth so that the contentprovider's server can send to the user streaming media data with aresolution appropriate for the indicated Internet connection'sbandwidth. Alternatively, the user might first indicate their bandwidthand then be given a choice of media to download from the contentprovider.

[0016] Optionally, the content provider's server could set a cookie onthe user's computer defining the bandwidth of the user's Internetconnection. By setting this cookie the user need not again indicate thebandwidth of their Internet connection when they return to the site.

[0017] Nevertheless, such manual selection of streaming media by theuser according to the bandwidth of the user's connection has severaldisadvantages. First, this requires the user to take action, which slowsthe user's browsing experience. Second, the user may select the wronglink; should the user inadvertently choose a link for a lower bandwidthconnection than is appropriate, the user will see a lower quality imagethat necessary. If the user selects a link for a higher bandwidthconnection than is optimal, the user's computer may not be able toreceive streaming media data at that rate. In such a case, the lack ofdata could cause playback to skip and jerk. In addition, if the userrefuses to allow a cookie reflecting the bandwidth of the user'sInternet connection to be set, or the user has deleted such a cookie,the user, when returning to the website, will again have to choose theappropriate download link when they return to the site and attempt todownload streaming media content. Each of these actions can contributeto user frustration, which may adversely affect site viewership.

SUMMARY OF THE INVENTION

[0018] The present invention is directed to a system for controlling thetransmission of data from a content provider to a user over the Internetbased upon the bandwidth of the user's connection to the Internet.

[0019] More particularly, this invention measures the bandwidth of auser's Internet connection each time a user requests data such asstreaming media data from a content provider and, having measured thebandwidth of the user's connection to the Internet, sends the user thedata in a form optimized for the measured bandwidth.

[0020] In a further embodiment, this invention determines the bandwidthof the user's Internet connection when the user first visits a contentprovider's site. The content provider then stores information regardingthe determined bandwidth and that stored information is used so that theuser is sent data optimized for the measured bandwidth. The storedinformation can be used only for the immediate session only, for apredetermined period of time, or even in separate sessions. By using thestored information the content provider avoids the need to again measurethe bandwidth of the user's Internet connection.

[0021] The present invention involves a method for measuring thebandwidth of a signal path between a data source and a data recipient.This can be done by sending a block of test data from the data sourcealong the signal path to the data recipient, using that test data tomeasure the time needed to transfer that data, and so obtain a measuredbandwidth of the signal path. Streaming media data or other informationis then transferred from the data source along the signal path to thedata recipient based upon the measured bandwidth. If desired, thebandwidth can be measured each time the data recipient visits thewebsite or the bandwidth can be stored for future use. The signal pathcan include the Internet and the information may be streaming mediadata.

[0022] A further and optional aspect of this invention involvesdetermining whether the measured time falls within a range and only ifthe measured time falls within that range is the measured time used todetermine a measured bandwidth of the signal path. If the measured timeis below the range, a different block of test data is sent along thesignal path to obtain a further measured bandwidth and transfer ofinformation takes place in accordance with the further measuredbandwidth. Should the measured time exceed the range, use of themeasured time to determine the bandwidth of the signal path is delayed.

[0023] Additionally, in an alternate embodiment, this invention includesdetecting whether the signal path's bandwidth was previously determined.If that bandwidth already was determined and is available then the knownbandwidth value is used, instead of measuring the bandwidth anew.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will now be described with reference to theaccompanying drawing figures, which are merely illustrative, and whereinlike reference characters denote similar elements throughout the severalviews. In these drawings:

[0025]FIG. 1 depicts a number of different computers connected via theInternet;

[0026]FIG. 2 is a detailed schematic diagram showing components of bothclient and server computers connected through the Internet;

[0027]FIG. 3 is a flowchart illustrating the exchange of data betweenclient and server computers in accordance with the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0028] The present invention is directed to methods of controlling anddisplaying data, in particular, streaming media data, using an Internetbrowser interface. More specifically, the present invention relates tothe transmission of streaming data from a server computer to a clientcomputer over the Internet, and to the measurement and characterizationof client's Internet connection. This enables the content provider tosend streaming media data to the user in the appropriate manner for thebandwidth of the user's Internet connection. As explained in greaterdetail below, this can be achieved by automatically sending a block oftest data from the content provider to the user.

[0029] Once the bandwidth of the user's Internet connection is measured,the content provider's server can send the requested data to the useralong with information establishing the format of the media playerwindow in which that data will appear. By way of non-limiting example,the information establishing the format of the media player window canbe sent, before the streaming data, in a separate file containinginformation such as a stream ID number, a stream identifier relating tothe format of the data that will be sent, the stream title, streamauthor, status and copyright information, the data transfer rate (i.e.,bit rate), the file name, the duration of the streaming data, and anexpiration. All or some of this data, and/or other data, could beincluded in the identifying file.

[0030] Next, server and client computers suitable for use with thisinvention will be described.

[0031] As depicted in FIG. 2, server 1 has a number of differentcomponents, each of which will be described hereafter, connected to abus 15. Bus 15 serves to relay commands and data between variouscomponents.

[0032] Central processing unit (CPU) 3 serves to control the internaloperation of the server. Read-only memory (ROM) 7 is a non-volatilememory device which stores programs and data used by the CPU 3 as theserver 1 starts up. Random access memory (RAM) 5 is a memory devicewhich contains programs and data used by the CPU 3 during routineoperation of server 1. Commands from an operator (not shown) are sent tothe server 1 through an input device 9, which could by way ofnon-limiting example be a keyboard or a pointing device such as a“mouse” or trackball. Server 1 displays information through output 11.Output 11 can, for example, be a video monitor or a printer. Operatingprogram and data files can be stored on an operation drive 13 a, anddata to be sent out from the server 1 to users can be stored on acontent drive 13 b. Drives 13 a and 13 b are preferably magnetic diskdrives. The use of different drives 13 a and 13 b to store the operatingprograms and data separate from the content data is thought to bepreferable because it facilitates the simultaneous reading of suchoperating information and content data. Moreover, although FIG. 2depicts the use of two separate drives 13 a and 13 b, additional drivesalso could be provided. Alternatively, a single drive could be used.

[0033] Various types of data can be stored on server 1 for transmissionover the Internet to users. Such data could, by way of non-limitingexample, take the form of HTML (hypertext mark-up language) web pages,images, text, programs, audio and video files. The server 1 cantherefore function as a data source. The present invention isparticularly applicable to the transfer of audio and video files, aswill be described hereafter.

[0034] Server 1 has a data port 16 through which the server 1 canexchange data over the Internet with external computers such as clientcomputer 20. By way of non-limiting example, the data port 16 could be acable modem, telephony modem or network connection. Data port 16 isconnected to the Internet by data line 18, which by way of non-limitingexample could be a coaxial cable, a telephone line, or an optical fiber,or any type of such connector now known or hereafter developed. Dataline 18 also could be a wireless connection such as a satellite link.

[0035] The present invention also could be adapted for use over anyknown or future developed networks other than the Internet. By way ofnon-limiting example, this invention could also be used over an Ethernetlocal area network.

[0036] In known fashion, server 1 has a unique IP (Internet protocol)address which identifies the server and distinguishes it from all othercomputers on the Internet.

[0037] Data is exchanged between server 1 and the Internet in accordancewith pre-established protocols. Requests for data from users and thedata sent in response can be exchanged using TCP/IP (TransmissionControl Protocol/Internet Protocol), UDP (User Datagram Protocol), orother protocols.

[0038] Next, client computer 20 will be described with reference to FIG.2.

[0039] Client computer 20 includes a bus 17 through which commands anddata flow between the client computer's different components. Centralprocessing unit (CPU) 19 controls internal operation of the client 20.Programs and data used by the CPU 19 during start-up are stored in aread-only memory (ROM) 23. ROM 23 is preferably a non-volatile memorydevice. A random access memory (RAM) 21 is another memory device andthis device contains programs and data that are used by the CPU 3 duringroutine operation of client 20. Storage device 25, commonly a magneticdisk drive, contains programs and data used by the client 20 duringoperation. Such programs include client software which enables theclient 20 to communicate with the server 1 over the Internet.

[0040] Commands are sent to the client 20 by an operator (not shown)using an input device 27, which could by way of non-limiting example bea keyboard or a pointing device such as a “mouse” or trackball. Output29 is provided to display information from the client 20, and can, forexample, be a video monitor or a printer. The information displayed mayrelated to the operating status of the client 20 or be controlled byprograms running on the client 20.

[0041] A removable storage device 37 can accept, read, and optionallyrecord data on removable media (not shown). By way of non-limitingexample, the removable media used by the removable storage device 37could be a magnetic floppy disk, compact disc (CD) device, a digitalvideo disc (DVD) or a memory card device. Also by way of non-limitingexample, the removable storage device 37 can be used to load programsfrom removable media onto the client 30, or save programs and data fromthe client 20 onto removable media.

[0042] Client 20 can exchange data with external sources such as server1 via a data port 31. Where data is to be exchanged over the Internet,data port 31, which by way of non-limiting example could be a cablemodem, telephony modem or network connection, is connected to a dataline 33, which by way of non-limiting example could be a coaxial cable,a telephone line, or an optical fiber. Data line 33 also could be awireless connection such as a satellite link.

[0043] Client 20 exchanges data over the Internet through an InternetService Provider (“ISP”) 35. When client 20 receives data from anexternal data source, client 20 functions as a data recipient. Datapasses over data line 33 between the ISP 35 and the data port 31. TheISP 35 is itself connected to the Internet in a known manner which neednot be discussed herein.

[0044] In known fashion, server 1 has a unique IP (Internet protocol)address which identifies the server and distinguishes it from all othercomputers on the Internet.

[0045] Client 20 could, by way of example only, be a personal computer.Alternatively, the client 20 could be a remote terminal which isconnected to a central mainframe computer, a WebTV® unit, or an Internetappliance, a low-cost device which eliminates many of a computer'scomponents, such as the hard disk drive.

[0046] As shown in FIG. 2, data can be sent from server 1 through dataport 16 to data line 18. The data then passes through the Internet 22 tothe ISP 35. ISP 35 sends the data to the client 20 over data line 33 todata port 31.

[0047] Since data transfer takes place over the Internet, data istransmitted between the server 1 and client 20 using Internet transferprotocols such as transfer control protocol and Internet protocol(TCP/IP). Such protocols are themselves known and need not be describedin detail herein.

[0048] As will now be described in greater detail with reference to FIG.3, the present invention checks at the content provider's side whetherthe bandwidth of the user's Internet connection already has beendetermined, and if not, tests that bandwidth. The streaming media datasent to the user is determined by the measured bandwidth.

[0049] In step S1 a user employs a browser to select and access acontent provider's website. The content provider's website has at leastone, and possibly many, hyperlinks (“links”) to streaming media content.By way of non-limiting example, links to other forms of content such asplain text, still images and/or audio files, as well as to otherwebsites, also may be provided on one or more pages. At least one of thecontent provider's web pages will contain one or more links which, whenactivated, send the content provider a request to download content tothe user. Activating (“clicking”) the hyperlink(s) to streaming mediacontent will request the content provider's website to send streamingmedia content to the user.

[0050] As explained in detail hereafter, the present invention willautomatically determine the bandwidth of the user's Internet connection,and control the supply of streaming media content accordingly. If thisis the user's first visit to the content provider's website thatinformation will be obtained, used and stored automatically. Should theuser have visited the website previously, the desired information mayalready be available in the form of a cookie, which is a file stored onthe user's client computer 20 to save information that can be used bythe content provider's server computer 1. The creation and use ofcookies is generally known and will not be described further.

[0051] The expression “activating a link” is used broadly and includesany manner of selecting a link so as to cause a suitable signal to besent from the user's browser back to the link's source. By way ofnon-limiting example, this can be done using a mouse, trackball orkeyboard, touch-sensitive display screen, or voice-activated software,or other components, in known fashion.

[0052] To assist a user in deciding whether to access streaming mediacontent, the link(s) to that content is preferably either itselfdescriptive or is accompanied by an explanation of the content which canbe accessed by following the link(s). For example, a link might read“click here to see an excerpt of a video showing the most recent WorldSeries.”

[0053] The term “content” is used in a broad sense, and by way ofnon-limiting example includes streaming media, video files, audio files,image files, text files and some combination thereof. The presentinvention is particularly suited to the transmission of streaming mediadata.

[0054] As previously noted, several different situations may exist withregard to the desired bandwidth: (1) regardless of whether the user haspreviously visited the content provider's site, bandwidth determinationis conducted anew and so there is no inquiry whether the user has acookie from a previous visit that might contain bandwidth-relatedinformation; (2) the user has never before visited the contentprovider's site, and so does not have a cookie with such information;(3) the user has visited the site previously but has not accepted acookie; (5) although the user has visited the content provider's siteand received a cookie, that cookie either has expired, does not containinformation regarding the user's Internet connection bandwidth, orotherwise has been deleted; and (5) the user has previously visited thecontent provider's site and still has a cookie.

[0055] Each of these different situations will now be described, whereappropriate, with reference to FIG. 3.

[0056] A user new to the content provider's site wishes to obtaincontent shown on the content provider's web page. To do this, the userin step S1 has his browser download web page data for the contentprovider's site,

[0057] If the content provider wishes to measure the bandwidth of theuser's Internet connection each time the user requests data from thecontent provider, it is not necessary to inquire whether the user has acookie from a previous visit. As shown in FIG. 3, the cookie inquiry ofstep S3 is not performed; instead, processing moves along branch A tostep S5, wherein the user selects the desired media. By using thisscheme, the bandwidth of the user's Internet connection can bedetermined each time the user requests data from the content provider.

[0058] Alternatively, it may be desired to see if the bandwidth of theuser's Internet connection was previously determined, for example, inresponse to a previous content request during the present session orduring a previous visit to the content provider's site. In such casesinformation regarding the bandwidth of the user's Internet connectionmay be contained in a cookie on the user's computer. In this case,processing advances by branch B to step S3, where an inquiry isperformed to determine whether the user's computer stores a cookie fromthe content provider's site.

[0059] Incidentally, a combination of these two approaches may be used.By way of non-limiting example, the content provider could immediatelymeasure the bandwidth of the user's Internet connection at apredetermined time, such as the first time the user visits the contentprovider's site each hour/day/week/month, and then store thatinformation using a cookie set on the user's computer. For apredetermined time thereafter, the content provider could look to theuser's computer for the cookie containing information regarding theuser's bandwidth. After that predetermined time, the bandwidth could bemeasured anew.

[0060] Returning to FIG. 3, if no cookie was found in step S3,processing advances to step S5, at which point the user selects thedesired content in step S5 (discussion of processing if the cookie isfound follows later). This can be done by choosing and activating thelink corresponding to the content of interest. The desired link can bechosen and activated in known fashion using a suitable input device,such as a keyboard, mouse, trackball or other manual pointing device, orvoice-recognition program. Activating the link sends a content requestto the content provider's website, and the content provider responds tothat content request by taking steps culminating in sending of therequested content back to the user. These steps will now be described indetail.

[0061] While the following discussion of the present invention assumesthat bandwidth of the user's Internet connection is determined by thequality of the user's connection to his ISP, this invention also couldbe used where other factors affect the user's Internet connectionbandwidth. For example, quality of the connection between the ISP andthe Internet backbone, or in other segments of the path followed by thedata being sent between the user and the content provider, mightdetermine the bandwidth of the user's Internet connection. Thus, thefollowing discussion of the present invention, while it speaks of theuser-ISP connection, also could be used where one or more of these othersegments influences the bandwidth of the user's Internet connection.

[0062] Once the user new to the site has selected in step S5 the desiredstreaming media, the content provider's server will take steps toevaluate the bandwidth of the user's connection to the Internet. It willbe appreciated that because generally the slowest part of the signalpath leading from the user's client computer 20 to the contentprovider's server 1 over the Internet is the signal path from the clientcomputer 20 to the ISP 35, only the bandwidth of that portion of thesignal path need be measured. It should be kept in mind that beforetaking steps to measure that bandwidth, the content provider already hasdetermined in step S3 that because no cookie was returned by the user'sbrowser, such information is not available on the user's computer.

[0063] By way of exemplary general overview, this invention can simplytransmit a test block of data to a user, or can include a subprocesswhich can wait, if necessary, for the cessation of transient Internetconditions that may interfere with the content provider's ability tojudge the user's bandwidth.

[0064] Where a block of test data is simply transmitted, a 5K block ofdata can be sent to test the user's bandwidth (other size data blockscould be used). This can be done with or without comparison to anexpected or maximum amount of time. If the 5K block of test data cannotbe sent, then the connection is of such low bandwidth that the contentprovider cannot adequately interact with the user. In that case, asuitable error message could be sent.

[0065] In the foregoing approach, bandwidth could be calculated basedupon the time that was required to transfer the block of test data. Thatvalue is used for comparison to determine the behavior of otherfunctionality or to determine the user's ability to accept variousstreaming media speeds.

[0066] If the subprocess which waits for Internet conditions to improveis used, in order to limit the time spent waiting for those transientconditions to end, part of this subprocess also can involve checking tosee that not more than a predetermined amount of time is spent waiting.

[0067] Another subprocess checks to see generally whether the user has ahigh speed Internet connection. This is done because it may be desirableto test the bandwidth of such a high speed using a more accurate testprocedure.

[0068] If the subprocess which waits for Internet conditions to improveis to be used, the content provider begins the bandwidth determinationprocedure in step S7 by first setting to 0 the value X of a loopcounter; if that subprocess is not used, step S7 can be omitted. Asexplained in greater detail below, this loop counter is used in thesubprocess to limit the amount of time spent evaluating the user'sbandwidth.

[0069] Next, the content provider “pings” (that is, sends to) the userin step S9 with a predetermined amount of data. By way of non-limitingexample, a 50 Kbyte block of test data can be sent to the user'scomputer. The block of test data includes an instruction causing theuser's computer to note and transmit back to the content provider thetimes that the first and last portions of the block of data are received(other schemes for measuring the time required for the complete receiptof the data block, such as measurement at the content provider's side,could be used). With this information the content provider can in stepS13 measure how much time is required for the user to receive the 50Kbyte block of data.

[0070] The optional subprocess for waiting to see if transient Internetdelays clear may be used because in some instances the test block'stransmission of test data to the user may be slowed not because of theuser's own connection with the ISP, but rather, because of suchtransient delays elsewhere in the Internet. For example, congestionalong the lines used to transmit data from the user's ISP to theInternet backbone will reduce the rate at which the ISP's customers cansend and receive data. Traffic over the Internet's high-speed backbonealso might delay the data being sent from the content provider to theuser, or the user's computer might be running other programs such asanti-virus software at the same time as the browser, which otherprograms use sufficient system resources to slow the browser's receiptof data from the Internet.

[0071] Such a delay may be so substantial that it slows the transmissionof the test block to the user to a rate less than that of even theslowest normal Internet connection. It can therefore be assumed thatwhenever the time needed to download the block of test data to the userexceeds the download time for the slowed expected connection(T>T_(max)), there is some other delay in the signal path. In otherwords, if it takes longer to transfer the block of test data than shouldbe the case using the slowest modem in common use, it can be inferredthat transient conditions exist somewhere along the data transfer pathwhich unduly lengthen the time needed to transmit the entire block ofdata. Thus, if this subprocess is used, then in step S15 a check is madeto see whether T>T_(max) (if the subprocess is not used, step S15 can beomitted).

[0072] When the present invention detects such a delay, the bandwidthdetermination process is deferred and periodically repeated in the hopethat the cause of the delay will abate. If the cause of the delay doesnot abate after a predetermined period of time, then a default bandwidthcan be assumed.

[0073] More specifically, if in the initial bandwidth measurementprocess the measured download time determined in step S13 exceeds thatfor the slowest connection that could be expected (T>T_(max)), it can beinferred that there is a transient delay somewhere along the data pathwhich is slowing data transfer (“Y” in step S15). In that case, theprocess flow could loop back to again ping the user, since by then thecause of the delay might have ended.

[0074] Such looping and pinging could continue indefinitely until thedelay ends and the true data transfer time (now no greater than theexpected maximum time) can be determined. Because this might halt thedownload of streaming media data to the user, it may be preferable toplace a limit on the amount of time spent by the user waiting while thecontent provider tries to detect the data transfer time to that which isreasonable and which will not try the user's patience. If by the end ofthat limiting time the user's bandwidth still has not been measured, adefault bandwidth BW_(d) can be assigned in step S21. A defaultbandwidth of 28.8 Kbits/sec could be used, for example, thiscorresponding to the speed of the slowest expected telephony modemspresently used.

[0075] As noted above, bandwidth could be determined on the basis of theamount of time taken to transfer the block of test data without waitingto see if the transient delay clears. In a further alternativeembodiment, and as explained below, transient delay could be inferredafter a period of time and suitable action taken.

[0076] The length of time after which transient delay can be inferredcan be determined by assuming a minimum connection speed. If the timerequired to transmit the entire block of data exceeds the time whichwould be required to transmit the data at that minimum connection speed,transient delay can be inferred. By way of non-limiting example, if itis assumed that the user's minimum connection speed to the ISP is 28.8Kbits/sec, then a 50 Kbyte block of data should not take more thanapproximately 13.8 seconds to be transmitted (50,000 Kbyte×8bits/byte)/28,800 bits/second=13.8 sec.). Here, if more than about 14seconds are required for the transmission of the entire block of data,transient delay can be inferred.

[0077] One benefit of this approach is that it keeps the user frombecoming frustrated with waiting and leaving the content provider'swebsite, even thought the user's bandwidth will not be determinedaccurately.

[0078] In summary, to implement this control option, the systemascertains in step S15 whether the elapsed time T is greater than thepredetermined maximum time T_(max), that predetermined maximum timereflecting a presumed minimum connection speed. If the elapsed timeexceeds the predetermined maximum time T_(max), processing continuesenters a delay loop. Each time processing passes through the loop theincremental counter X is advanced by 1 in step S11. Again, it should beunderstood that this procedure of comparing to a predetermined value isoptional, and could be omitted in favor of an immediate determination ofbandwidth in the manner already described.

[0079] To limit the time spent in this loop, in step S23 a check is madeto see whether the counter value has reached a predetermined maximumvalue, X_(m). If in step S23 it is determined that X exceeds X_(m),processing moves to step S21, where a default value of BW_(d) isassigned for bandwidth BW. It will be understood that the check in S23is not needed where bandwidth is directly measured and the effect of anytransient delay ignored.

[0080] If in step S23 it is found that X is less than X_(m), thenprocessing continues through the loop back to step S9, where pinging isperformed, in the manner outlined above.

[0081] With continued reference to step S15, if it is determined in stepS15 that the transmission time is less than the aforementioned presumedmaximum time T_(max), meaning there is not an external delay affectingthe bandwidth of the user's Internet connection, processing advances tostep S17.

[0082] In step S17 the measured transmission time T is compared to aminimum transmission time T_(min). By way of non-limiting example, andas shown at step S17, this determination of a high bandwidth connectioncan be made by comparing the measured time T to reference time T_(min),reference time T_(min) having been chosen to correspond to the timerequired for a high bandwidth connection to transfer 50 Kbytes of data.This is done because as transmission time decreases, measurement errorsmay increase. In that case, it may be desirable to re-test thetransmission time using a larger block of test data, as will bedescribed later in greater detail. This scheme can be used for both thedirect measurement of bandwidth and the alternative “looping andpinging” schemes.

[0083] If the measured transmission time T does not exceed the minimumtime T_(min) (in step S17, “N”), the process will continue to step S19,where the bandwidth corresponding to time T is determined using the timemeasured in step S13. One way to determine the bandwidth is to use themeasured transmission time to calculate the bandwidth of the user'sconnection to the Internet according to the formula:

BW=D/T  (1)

[0084] where BW=bandwidth, D is the amount of test data sent (here, 50Kbytes), and T is the amount of time required to completely send thetest data to the user. While BW is here calculated in terms ofKbytes/second, BW can be converted to Kbits/second simply by multiplyingthe value of BW by the conversion factor of 8 bits/byte.

[0085] As an alternative to direct calculation of bandwidth, thebandwidth BW could be determined by using a look-up table correlatingdifferent measured times to different bandwidths values. The look-uptable and the values contained therein can be generated in advance onthe basis of actual measurements and/or theoretical calculations. Suchnumbers could vary according to the application involved (i.e., thenature of the streaming media data that is sent).

[0086] For example, the look-up table could contain a number ofdifferent measured time ranges forming the limits of several ranges(T_(a)-T_(b)), together with the associated bandwidth values, as shownin Table 1: TABLE 1 T_(a) (sec) T_(b) (sec) Bandwidth 14.0 9 30Kbits/sec 9 5 60K bits/sec 5 3 90K bits/sec

[0087] These values are only provided by way of example and notlimitation. More ranges, narrower ranges and/or other values could beemployed.

[0088] As previously noted, a check is made in step S17 to see whetherthe user's Internet connection is a high bandwidth connection. When itis found in step S17 that time T<T_(min), this means that the user'sbandwidth is of at least a certain threshold speed, and so a further andmore accurate test can be performed. Also by way of non-limitingexample, means in the form of programmable circuitry (not shown) orsoftware may be provided so that the value of the reference time T_(min)could be changed. It may be helpful to be able to change the referencetime because over time the average bandwidth increases as users upgradetheir connections and higher bandwidth devices are prepared.

[0089] Taken together, steps S15 and S17 involve checking to see whetherthe measured time required to download the block of test data fallsoutside the time range T_(min)-T_(max). Only if T falls within thatrange is the bandwidth immediately determined. If T is shorter thanT_(min) a more detailed bandwidth test is performed in step S25, whileif T exceeds T_(min) measurement is delayed for a period and, ifnecessary, a default bandwidth is presumed in step S21.

[0090] When the measured transmission time T is less than the minimumtime T_(min), a further measurement of transmission time is made in stepS25 by pinging the user with a 500 Kbyte block of test data. The 500Kbyte block of test data can be sent to the user in generally the samemanner as the 50 Kbyte test block, and other amounts of data could beused. The time required for the complete transmission of this data ismeasured in step S27, and the bandwidth is calculated in step S29. Thebandwidth can be calculated either using formula (1) or a suitablelook-up table, or some other technique.

[0091] The bandwidth value determined in either of steps S19, S21 or S29is then stored in step S30 for later use in controlling the transmissionof data to the user's browser.

[0092] Optionally, a cookie, either persistent or session, containinginformation reflecting the user's measured bandwidth is set on theuser's computer in step S31. Since the manner of setting a cookie isgenerally known, that operation will not be described in detail.

[0093] By setting this cookie in the user's computer, it will not benecessary to again determine the bandwidth of the user's connection thenext time the user seeks to download data from the content provider,whether in the current session or, if the user leaves the contentprovider's site, the next time the user returns to that site. This waythe time-consuming measurement procedures outlined above can be avoided.This aspect of the invention will be described in greater detail lateron.

[0094] Having determined the bandwidth of the user's Internet connectionand the available media player(s), the content provider in step S33 usesthis information to send to the user's browser a call to open up aparticular media player window. This can be done, by way of non-limitingexample, by sending the information establishing the format of the mediaplayer window before the streaming data, in a separate file containinginformation such as a stream ID number, a stream identifier relating tothe format of the data that will be sent, the stream title, streamauthor, status and copyright information, the data transfer rate (i.e.,bit rate), the file name, the duration of the streaming data, and anexpiration. All or some of this data, and/or other data, could beincluded in the identifying file.

[0095] If the user's computer does not have the correct type of mediaplayer for the data to be downloaded, the user's computer may in knownmanner give the user the option of downloading and installing thenecessary media player.

[0096] Knowing the user's bandwidth allows the content provider's mediaplayer call to specify the proper size of the media player window to beopened (again, the size of the media player window will be influenced bythe bandwidth of the user's Internet connection; faster connectionsallow for larger media player windows). By way of non-limiting example,the following media player window sizes could be used for the indicatedbandwidths: TABLE 2 Bandwidth Window Size  28K 176 × 132 pixels  56K 176× 132 pixels 100K 240 × 180 pixels 300K 320 × 240 pixels

[0097] The values proposed in Table 2 are proposed for a basic videowindow, and are suggested by way of non-limiting example. The windowsize may be altered if ActiveX controls are used.

[0098] This avoids degraded performance, which might otherwise occurwhere the user's bandwidth is insufficient to supply the needed amountof content data to the media player.

[0099] Once the user's computer has confirmed that the media playerwindow has opened, the content provider then commences transmitting datato the media player in step S35. After sufficient data has been receivedby the user's computer, the media player begins playing in step S37.

[0100] It is presently preferred to evaluate the user's bandwidth eachtime the user visits the website. This is thought to be preferablebecause of the inconsistency in bandwidth today; a user may have highbandwidth on one visit, low bandwidth on another. This way, thestreaming media data sent to the user is always tailored to reflect theuser's bandwidth.

[0101] Alternatively, instead of detecting the user's bandwidth eachtime a user visits a website, a previously-determined bandwidth can beused.

[0102] In the case where a previously-determined bandwidth is to beused, as noted above with regard to step S3, the user seeking todownload content from the content provider's site already has visitedthe content provider's site. In step S3 a check is made to see whether acookie for the content provider's site was set on the user's computerduring the previous visit. If the cookies has been set on the user'scomputer, the user's browser will in step S3 return that cookie to thecontent provider along with the user's initial request to be sent webpage data to display that site. Upon receiving this cookie the contentprovider's website will recognize the user as a repeat visitor.Processing advances to step S39, where a check is made to see ifbandwidth data is present in the cookie. If such data is available, thedata is then read out in step S41 and stored at the content provider foruse in selecting the format of streaming data sent to the user.

[0103] Having the previously-determined bandwidth data is useful becausethis information speeds the transmission of content to the user; now, itis not necessary to go through the various steps required to ascertainthe user's bandwidth. Content transmission can instead beginimmediately. The content to be downloaded from the content provider isselected by the user in step S43. Processing then advances to step S33,wherein the content provider uses that information to send to the user'sbrowser a call to open up a media player window and thereafter play thecontent in a manner already described with regard to steps S35 and S37.will take the steps already described with regard first to step S5 todetermine the user's bandwidth.

[0104] It will be understood that various values given in the foregoingdiscussion of this invention are by way of example and not limitation.For instance, blocks of test data of sizes other than 50 Kbytes and 500Kbytes, and other types of test data, could be used.

[0105] Likewise, while the foregoing discussion of this invention madereference to streaming media data, this present invention need not belimited to such data. Rather, the this can be employed whenever the sizeof data being transmitted is such that receipt of such data is aconcern. For example, this invention might have applicability to a gamesite.

[0106] Nor is the present invention intended to be limited to thetransmission of data over the Internet. This invention may haveapplicability in any network, such as a LAN, or other networks usingother transmission protocols, where the amount of data transferredbetween points on the network affects applications running on members ofthe network.

[0107] Thus, while there have been shown and described and pointed outfundamental novel features of the invention as applied to preferredembodiments thereof, it will be understood that various omissions andsubstitutions and changes in the form and details of the disclosedinvention may be made by those skilled in the art without departing fromthe spirit of the invention. It is the intention, therefore, to belimited only as indicated by the scope of the claims appended hereto.

What is claimed is:
 1. A method for measuring a bandwidth of a signalpath between a data source and a data recipient, comprising the stepsof: sending a block of test data from the data source along the signalpath to the data recipient; using that test data to obtain a measuredbandwidth of the signal path; and transferring information from the datasource along the signal path to the data recipient in accordance withthe measured bandwidth.
 2. A method according to claim 1, wherein thesignal path includes the Internet.
 3. A method according to claim 1,wherein the information comprises streaming media data.
 4. A methodaccording to claim 1, further comprising the step of storing themeasured bandwidth for a future use.
 5. A method for measuring abandwidth of a signal path between a data source and a data recipient,comprising the steps of: detecting whether the bandwidth of the signalpath was previously determined; if the bandwidth of the signal path wasnot previously determined, sending a block of test data from the datasource along the signal path to the data recipient and using that testdata to obtain a measured bandwidth of the signal path; and transferringinformation from the data source along the signal path to the datarecipient in accordance with either the previously determined bandwidthor the measured bandwidth.
 6. A method according to claim 5, wherein thesignal path includes the Internet.
 7. A method according to claim 5,wherein the information comprises streaming media data.
 8. A methodaccording to claim 5, further comprising the step of storing themeasured bandwidth for a future use, if the block of test data has beensent.
 9. A method for measuring a bandwidth of a signal path between adata source and a data recipient, comprising the steps of: sending ablock of test data from the data source along the signal path to thedata recipient and measuring a time required for the test data to betransferred to the data recipient; determining whether the measured timeis at least a threshold value and, if the measured time is at least thethreshold value, using the measured time to determine a measuredbandwidth of the signal path; and transferring information from the datasource along the signal path to the data recipient in accordance withthe measured bandwidth.
 10. A method according to claim 9, wherein ifthe measured time is less than the threshold value, a different block oftest data is sent along the signal path to obtain a further measuredbandwidth and the transferring of the information from the data sourcealong the signal path to the data recipient takes place in accordancewith the further measured bandwidth.
 11. A method according to claim 10,wherein the different block of data is larger than the block of testdata.
 12. A method according to claim 9, wherein if the measured time isat least the threshold value, the using of the measured time todetermine a measured bandwidth of the signal path is delayed.
 13. Amethod according to claim 12, further comprising a step of setting themeasured bandwidth to a default value if an amount of delay exceeds apredetermined time.
 14. A method according to claim 9, wherein thesignal path includes the Internet.
 15. A method according to claim 9,wherein the information comprises streaming media data.
 16. A methodaccording to claim 9, further comprising the step of storing at leastone of the measured bandwidth and the further measured bandwidth for afuture use.
 17. A method for measuring a bandwidth of a signal pathbetween a data source and a data recipient, comprising the steps of:detecting whether the bandwidth of the signal path was previouslydetermined; if the bandwidth of the signal path was not previouslydetermined, sending a block of test data from the data source along thesignal path to the data recipient and measuring a time required for thetest data to be transferred to the data recipient; if the bandwidth ofthe signal path was not previously determined, determining whether themeasured time is at least a threshold value and, if the measured time isat least the threshold value, using the measured time to determine ameasured bandwidth of the signal path; and transferring information fromthe data source along the signal path to the data recipient inaccordance with either the previously determined bandwidth or themeasured bandwidth.
 18. A method according to claim 17, wherein if themeasured time is less than the threshold value, a different block oftest data is sent along the signal path to obtain a farther measuredbandwidth and the transferring of the information from the data sourcealong the signal path to the data recipient takes place in accordancewith the farther measured bandwidth.
 19. A method according to claim 17,wherein the different block of data is larger than the block of testdata.
 20. A method according to claim 17, wherein if the measured timeis at least the threshold value, the using of the measured time todetermine a measured bandwidth of the signal path is delayed.
 21. Amethod according to claim 20, further comprising a step of setting themeasured bandwidth to a default value if an amount of delay exceeds apredetermined time.
 22. A method according to claim 17, wherein thesignal path includes the Internet.
 23. A method according to claim 17,wherein the information comprises streaming media data.
 24. A methodaccording to claim 18, further comprising the step of storing at leastone of the measured bandwidth and the further measured bandwidth for afuture use.